In 2010, Nicolas Giuseppone and his colleagues at the Charles Sadron Institute chemically modified triarylamines, synthetic molecules that industry has been using for decades in Xerox photocopying processes, and observed them in light and in solution, thus obtaining nanowires. The fibers, a few hundred nanometers long, are made of what is known as the 'supramolecular' assembly of several thousand molecules.
During another stage where they worked with Bernard Doudin's team at the Strasbourg Institute of Material Physics and Chemistry (IPCMS), they studied the electric properties of the nanowires. To do so, they placed the molecules in contact with an electronic microcircuit with gold electrodes at 100-nanometer intervals and then applied an electric field between the electrodes. They observed that, when triggered by a flash of light, the fibers self-assembled only between the electrodes. The structures, which are as light and flexible as plastics, are also able to transport extraordinary current densities, above 2.106 Amperes per square centimeter, approaching the densities of copper wire. They also have very low interface resistance with metals, i.e. 10,000 times below that of the best organic polymers.
The researchers now hope to demonstrate that their fibers can be used industrially in miniaturized electronic devices (i.e. flexible screens, solar cells, transistors, printed nanocircuits). The results of their research were published in the advance online edition of Nature Chemistry on April 22.